Hi. I have an 06 Carrier XTC that keeps throwing a code A13 for high discharge pressure. When, I ran a pre-trip, I got a code P164, "Check UL2 Circuit", in Test 2 of the pre-trip, and the pre-trip failed.

Any idea on what it could be or what I should check? Thanks.

IRMechanik

18-08-2014, 05:34 PM

Hi. I have an 06 Carrier XTC that keeps throwing a code A13 for high discharge pressure. When, I ran a pre-trip, I got a code P164, "Check UL2 Circuit", in Test 2 of the pre-trip, and the pre-trip failed.

Any idea on what it could be or what I should check? Thanks.

What's your discharge pressure running? Is it actually running high pressure or is it an electrical problem? when is it tripping the a13 code? Is it in cool or heat/defrost?

The unloader code is probably a broken wire at the unloader coil. Fix that first, the pretrip will fail there and go no further. Once that's fixed run the pretrip again and see what else it finds. Could be as simple as an open SV4 coil, need more information.